Fix server crash on shutdown (issue #9054)

Players are only saved by the player save thread on shutdown now.
PlayerManager::saveAll is still dubious and should be removed, as it
can easily crash the server.

All threads are terminated regularly now (join).
Improve logging for maps

Less verbose, log single maps on error only.
Merge branch 'range_search' into testserver
Fix issue #8565: double login
Remove dangerous method PlayerManager::saveAll
Add missing include
Fix CharacterContainer insert/update